Method for Functionalization of Nanoscale Fiber Films

Abstract

Methods are provided for functionalizing a macroscopic film comprised of nanoscale fibers by controlled irradiation. The methods may include the steps of (a) providing a nanoscale fiber film material comprising a plurality of nanoscale fibers (which may include single wall nanotubes, multi-wall nanotubes, carbon nanofibers, or a combination thereof); and (b) irradiating the nanoscale fiber film material with a controlled amount of radiation in the open air or in a controlled atmosphere. The step of irradiating the nanoscale fiber film material is effective to functionalize the plurality of nanoscale fibers. Irradiated nanoscale fiber films are also provided having improved mechanical and electrical conducting properties.

1 . A method of functionalizing a nanoscale fiber film material, comprising the steps of:
 (a) providing a nanoscale fiber film material which comprises a plurality of nanoscale fibers; and   (b) irradiating the nanoscale fiber film material with a controlled amount of radiation, wherein the radiation comprises an ion-particle beam or ultra-violet beam.   
     
     
         2 . The method of  claim 1 , wherein the step of irradiating the nanoscale fiber film material is effective to functionalize the plurality of nanoscale fibers. 
     
     
         3 . The method of  claim 1 , wherein the step of irradiating the nanoscale fiber film material increases the tensile strength and modulus of the nanoscale fiber film material. 
     
     
         4 . The method of  claim 1 , wherein the step of irradiating the nanoscale fiber film material increases the toughness of the nanoscale fiber film material. 
     
     
         5 . The method of  claim 1 , wherein the step of irradiating the nanoscale fiber film material increases the electrical and thermal conductivity of the nanoscale fiber film material. 
     
     
         6 . The method of  claim 1 , wherein the step of irradiating the nanoscale fiber film material creates cross-links, interconnections, junctions, or a combination thereof, in the plurality of nanoscale fibers. 
     
     
         7 . The method of  claim 1 , wherein the step of irradiating the nanoscale fiber film material increases interfacial bonding in the plurality of nanoscale fibers. 
     
     
         8 . The method of  claim 1 , wherein the step of providing the nanoscale fiber film material comprises:
 (a) suspending the plurality of nanoscale fibers in a liquid medium; and   (b) removing the liquid medium by at least one of filtration and vaporization to form the nanoscale fiber film material.   
     
     
         9 . The method of  claim 1 , wherein the nanoscale fiber film material has a thickness in the range from about 5 to about 50 microns. 
     
     
         10 . The method of  claim 1 , wherein the plurality of nanoscale fibers comprise a plurality of carbon nanotubes. 
     
     
         11 . The method of  claim 1 , wherein the ion-particle beam radiation has an energy greater than 50 eV. 
     
     
         12 . A nanoscale fiber film material comprising a plurality of nanoscale fibers, wherein the plurality of nanoscale fibers have been functionalized by a controlled irradiation process, wherein the nanoscale fiber film material has a thickness between 5 and 50 microns. 
     
     
         13 . The nanoscale fiber film material of  claim 12 , wherein the nanoscale fiber film material has increased tensile strength relative to that of a non-irradiated nanoscale fiber film material of the same construction. 
     
     
         14 . The nanoscale fiber film material of  claim 12 , wherein the nanoscale fiber film material has increased toughness relative to that of a non-irradiated nanoscale fiber film material of the same construction. 
     
     
         15 . The nanoscale fiber film material of  claim 12 , wherein the nanoscale fiber film material has increased electrical and thermal conductivity relative to that of a non-irradiated nanoscale fiber film material of the same construction. 
     
     
         16 . The nanoscale fiber film material of  claim 12 , comprising a plurality of cross-links, interconnections, junctions, or a combination thereof, between or among the plurality of nanoscale fibers. 
     
     
         17 . The nanoscale fiber film material of  claim 12 , wherein the plurality of nanoscale fibers comprise a plurality of carbon nanotubes.